Răspuns:
1. c) 29
2. d) p.p
3. d) 2 la puterea 2
4. a) 125.247
1. 11x(a+b)=p.p
AB =?
a+b=11
a=2,3,4,5,6,7,8,9
b=9,8,7,6,5,4,3,2
AB =29, 38, 47, 56, 65, 74, 83, 92
3. 2 La puterea 24 :4 = 2 la puterea 24 : 2 la puterea 2 = 2 la puterea 22
4. S= 7+11+15+...+999
7=4x1+3
11=4x2+3
15=4x3+3
.
.
.
999=4x249+3
S= 4x (1+2+3+....+249) +3x249
S=4x249x259:2+747=125.247